Radio signaling system



' Patented Apr. 21, 1931 UNITED STATES PATENT OFFICE MARIUS LATOUR, OF PARIS, FRANCE, ASSIGNOR TO LATOUR CORPORATION,

l CITY, NEW ERSEY, .A CORPORATION OF DELAWARE OF JERSEY RADIO SIGNALING SYSTEM Application filed August 19, 1921, Serial No. 493,665, and vin France September 27, 1915.

.(GRANTED UNDER THE PROVISIGNSVOF THE ACT 0F MARGH 3, 1921; 41 STAT. L., 1313) Application filed in France, September 27, 1915, patented `February 28, 1920, under 50eme. Y

`In electrical vacuum tube relays (or tubes 'filled' with ionized atmosphere) that `have been suggested by various inventore-it may be advantageous under certain conditions (radiotelegraphic or radiotelephonic receiving on airplanes, receiving station located near an industrial network)` to substitute an alternating potential source in place of the battery inserted in Vthe plate-filament circuitv of the said relay. By means of transformers, this alternating potential may .i be stepped up to the desired value.

'A local alternating current source being available, the desired object may be attained by transforming the characterl of the current through the agency of twolkenotrons of the General Electric Company type and to return to the condition of direct current potential. Butin thiscase, the resistance of the lrenotrons is introduced into the circuit and it may be found advantageous directly to utilizethe alternating potential without changing its characterf'lhis may be accomplished in the followingmanner, Vreference being had to the accompanyingdrawing vin which f' Fig. 1 diagrammatically representsy a netpull relation -respGCtVelywork including a vacuum tube in which the usual direct current plate supply source is Vreplaced by'a source of alternating current.

Figs. 2 and 2a are modifications of 1 showing the 'use of two vacuum tubes connected in push-pull relation in a similar network.

Fig. 3 is a modification of Fig. 1 for a system employing a dduble-element tube, in which the input and output electrode are connected-in push-pull relation.

Fig. 4 is amodication of Fig. 3 for a system inwhich the input and output electrodes are connected in parallel and push- In accordance with the invention, as illustrated, in Fig. l of the drawings, the usual batteryof the plate-filament circuit P, F is replaced by a network of any periodicity f1, which, however, is different from the periodicity f2 of the current to be amplified. lVhile the potential of f2 frequency is not applied to the grid filament circuit GF, the tone corresponding to frequency fl will be heard in the vtelephone T. As soon as the potential of f2 frequency actuates the grid filament circuit, in f1 periods, the tone of f2 heard but the fused. Y

In accordance with the present-invention, a circuit arrangement is provided for eliminating from the telephone circuit the tone corresponding to the frequency f1 of the network` and for bringing out the tone corresponding to the current to be amplified, the frequency of which is f2. Fig. 2 represents such circuit two tubes L and L Thevsecondary wiiulings of the induction coils B, B are 4connected in opposition andthe source of f2 frequency operatcsthrough a transformer, the middle point of the secondary. winding E of which is connected with the filaments F periods will be latter will e slightly convand F It will be seen, the1'efore,that the effects of the current of fl frequency will be, subtracted from each otherv in the telephone T, while the tones of f2 periods emanating from the two tubes will be added to each other in this telephone. If the `two tubes are exactly alike, the tone corresponding'to frequency fl may be completely eliminated. The best conditions for this circuit arrangement are obtained with a single tube provided with two plates and two grids, e. g. the special tube manufactured by the General Electric Company. A circuit arrangement in which a single tube of this type is used is shown inF ig. 3. The operation of addition to the tone of arrangement comprising Y' v CVT:

this circuit will be clear from what has been said in connection with Fig. 2.

lf continuous radio telegraphic waves are used, a detector D, as illustrated in Figure 2o, should be provided in each of the telephone circuits at points ce on Figures 2, 3 and 4:. The proposed circuit arrangement is a circuit for direct receiving, the alternating current source performing the function of a ticker.

lilith four tubes or two tubes of the special type, the character of the tone of f2 periods which exists with the circuits of Figs. l and 2 may be further improved.

Fig. l shows an improved circuit arrangement in which a single tube is used. rl`he tone correspomlino to frequency ,fl is eliminated by means r an auxiliary winding a provided on the single transformer l. The effect of this winding a is regulated by means of a resistance l. represents an aufo-transformer divided into two equal parts between which one of the three windings of the transformer is connected. The middle point of this winding is connected fo the common filament F, and the winding may be divided into two sections connected in series with the plates ll and P, respec- Aively, etc.

rlhis circuit arrangement uses two half waves of the 7"'1 frequency network, which replaces the usual direct current source and malres thus possible the use of the relay for wireless or wire telephone. ln the case of wireless telephony, the same machine could be alternately used either as a generator, by utilizing the well known lleissnerc-ircuit arrangement for producing high frequency currents, or with the present circuit as a source of /fl frequency. lhe arrangement has particular advantages in case a very light station is ired for air*L the saine etat-ion comprising sending as all as rec=iiving means.

laying described my invention, what l. claim is:

wireless telegraph receivi adapted for reception of i ing high frequency waves wherein the interruptions correspond to the paces between the dots and dashes of 'apli signals, said systems comprising a circuit including a source of fluctuating current of audil le frequency, an indicating device, said circuit being normally so balanced esito respect to said indicating device and said source of current that said indicating device is substantially unaffected by said luctu ating current, and means responsive to incoming signal impulses for upsetting the aforesaid balanced condition coincidentally with the duration of the incoming signal impulses whereby said fluctuating current is rendered effective to actuatc said indicating device and thereby reproduce the signal impulses.

ric.

2. A wireless telegraph receiving system adapted for reception of interrupted incoming high frequency waves wherein the interruptions correspond to the spacing of the signal impulses, said system comprising a circuit including a source of fluctuating current, translating device, said circuit being normally so balanced with respect to said device and said source of current that said translating device is substantially unaffected by said fluctuating current, and means responsive to the incoming signal impulses for upsetting the aforesaid balanced condition coincidentally with the duration of the incoming signal impulses whereby said liuctuating current is rendered eifect've to actuate said translating device and thereby to enable thc rein'oduction of the signal impulses.

3. A high frequency wave signal receiving system adapted to receive wireless telegraph signals, said system comprising a plurality of three-electrode vacuum tubes each having an input circuit and an output circuit, a source of alternating current of audible frequency for energizing said output circuits, a signal indicating device operatively associated with at least one of said output circuits, balancing means normally operable to prevent said fluctuating current from actuating said signal indicating device, and means responsive to incoming signal waves to upset the normal balanced condition whereby said indicating device is actuated by said fluctuating current in conformity with incoming signal wave impulses.

Il. In a wireless telegraph receiving system, a source of incoming signal waves, two complementary circuits, each including a space discharge path and an impedance in series therewith, a source of fluctuating space current of audible fre uency, said source being connected to bolli of said complementary circuits and adapted to supply the space current for said discharge paths, an additional circuit coupled with said complementary circuits conjointly, said complementary circuits being normally balanced oppositely in their effect upon said additional circuit so that normally there is substantially no fluctuating current of audible frequency in said additional circuit, a signal indicating` device responsive to audibly 'fluctuating current in said additional circuit, and an input circuit operatively associated with said complementary circuits conjointly and operable to upset the aforementioned balanced condition upon being energized by incoming signal waves, said input circuit being coupled to said source of incoming signal waves, the arrangement being such that said additional circuit is energized by said source of fluctuating space current coincidentally with the duration of the unbalanced condition.

5. In a wireless telegraph receiving sys- (ffl tem, a source of incoming signal waves, a pair of three-electrode vacuum tubes each havlng an input circuit and an output circuit, said input circuits being coupled con` jointly to said source of incoming signal waves, said output circuits each including the space discharge path of one of said tubes respectively, a source of alternating current connected to supply space current to both of said output circuits, and a signal indicating device operatively coupled to said output circuits conjointly, said output circuits being electrically balanced in their norma-l relation to said indicating device so that in the absence of incoming signal waves the fluctuating space current in said output circuits does not materially aiect said indicating device, said incoming circuits each including a control element, which elements are interposed respectively in the two discharge paths of said output circuits and operable to oppositely vary the impedance of said discharge paths in response to energization of said input circuits by incomingv signal waves thereby upsetting the equipoise of said output circuits and permitting said alternating space current to actuate said indicating device to reproduce the signals.

6. The method of signaling by means of electric waves interrupted in accordance with telegraph signals which comprises, identically impressing across a pairrof ionized space paths a` fluctuating voltage, lcausing the resulting space currents to ilow in opposition whereby normally the resultant effect is substantially zero, oppositely controlling said space currents with said electric waves, whereby additive space currents are produced, and causing said additive currents to be suitably indicated. p

7. The method of signaling by means of electric waves interrupted in accordance with telegraph signals which comprises identically impressing upon a pair of ionized space paths an alternating voltage, causing the resulting space currents to flow 1n opposition whereby normally the. resultant effectV is substantially zero, oppositely controlling said space currents with said electric waves whereby additive space currents are produced, and producing indications by means of said additive currents.

8. In a radio telegraph system, the method of signaling which comprises, identically impressing upon a pair of Vionized space paths, a voltage alternating at audio frequency, causing the space currents to flow in opposition whereby normally the resultant ei'lect is substantially zero, oppositely controlling said space currents with unmodulated electric waves of radio frequency interrupted in accordance with telegraph signals for producing additive space current components and causing said additive currents to be indicated.

9. In a radio `telegraph system, the method of signaling 'which comprises identically impressing Vupon a pair of ionized space paths an alternating voltage, causing the resulting space currents to flow in opposition whereby normallyv the resultant effect is substantiallyV zero, oppositely controlling said'space currents with radio telegraph signals `to produce Vadditive space currents, detecting and indicating the resulting currents.V l0. ln a radio telegraph system, the method of signaling which comprises,identically impressing upon a pair of ionized space paths a voltage alternating at 'audio `frequency, causingthe space currents to flow in opposition for normally producing substantially zero resultant eilect, oppositely controlling said space currents with continuous wave radio-frequency telegraph signals to produce additive modulated currents, detecting and receiving the resulting currents.

ll. ln a radio-frequency telegraph system, the method of signaling which comprises identically impressing upon a pair of ionized space paths, unmodulated radio frequency waves interrupted in accordance with telegraph signals, oppositely controlling said space currents at an audio frequency to produce additive modulated space currents,detecting and receiving the resultant currents.

l2. In a radio telegraph system the method of signaling which comprises, identically Y impressing upon a pair of ionized space paths a voltage alternating at a certain frequency, causing thejspace currents to flow in opposition whereby normally subst-antially no resultant eilect is produced, oppositely controlling said space currents with electric waves of a second frequency interrupted in accordance with telegraph signals to produce additive modulated space currents, detecting and indicating the resultant currents.

.18. In a radio telegraph system the method of signaling which comprises, identically impressing upon a pair of ionized space paths a fluctuating voltage, causing the space currents to flow in opposition whereby normally substantially no resultant effectis produced, oppositely modulating said space currents in accordance with radio telegraph signals for producing additive effects,l detecting and receiving said modulated currents. Y

la. rlhe method of radio signaling which comprises, identically impressing upon a pair of ionized space paths an alternating voltage, causing the space currents to flow in opposition to normally annul one another, oppositely modulating said space currents with unmodulated radio-frequency signaling waves interrupted in accordance ISD With telegraph signals to produce additive resultant space currents, detecting and receiving the modulated space currents.

l5. In a radio system the method of signalin(T which comprises identically impress- 5 ing upon a pair of ionized space paths a voltage alternating at audio-frequency, causing the space currents to flow in opposition to normally annul one another7 oppositely modulating said space currents in accordance with interrupted single frequency radio telegraph signaling currents to produce additive modulated space currents, detecting and receiving the resultant currents.

MARIUS LATOUR. 

